In recent years, lighting control systems (LCSs) have become increasingly popular, despite their prohibitive cost. A conventional LCS, or similar system for controlling electrical appliances, is used in a local environment, such as a home. The utility of the conventional LCS is to allow a user to control a distributed network of lights or other electrical appliances from a central location within the local environment. The ability to control electrical appliances from a central location, remote from the actual site of many of the electrical appliances, is convenient and otherwise advantageous.
Prior to use, the conventional LCS must be installed. Installation involves the initial configuration of a central control module and numerous appliance modules. Each of the various electrical appliances in the local environment is connected to a dedicated appliance module. Typically, the appliance module is located in close proximity to the associated electrical appliance. The various appliance modules are coupled to a common communications network that is linked to the central control module. The central control module and the appliance modules can communicate over various transmission media, including a common powerline for delivering power over the communications network. Through appropriate setting of rotary switches provided as the central control module and the appliance modules, the central control module identifies the appliance modules by assigning each appliance module with a code. The provision of appropriate commands to the central control module allows the user to control the operation of the electrical appliances from the central control module. In this way, the conventional LCS obviates the need for the user to visit the location of each individual electrical appliance to control its operation.
Although it offers some advantages, the conventional LCS poses many significant drawbacks. In particular, the design of conventional LCSs results in undue inconvenience and inefficiency during use. For example, the appliance modules allow the user to control the electrical appliances from a central location. However, the appliance modules are designed so that the electrical appliances cannot be controlled locally by providing direct commands to the appliance modules. If the user is in the vicinity of a particular electrical appliance and its associated appliance module, the user would be required to relocate to the central control module to control and operate the electrical appliance. Quite apparently, the design of the conventional LCS, in many instances, sacrifices the very convenience it is designed to provide.
Many other features of the conventional LCS render its use inconvenient. For example, the conventional LCS has a variety of appliance modules under the control of a single central control module, as stated above. The provision of the single central control module only, and no other means for controlling the various appliance modules, is burdensome, especially when the conventional LCS is implemented in a physically large environment. In this regard, assume that the user is situated near a particular electrical appliance, which is remote from the central control module. To control the electrical appliance, the user would have to travel the entire distance from the electrical appliance to the central control module. In a physically large environment, the time and effort to travel that distance could be unduly burdensome. Thus, the failure to implement more than one central control module is problematic.
As a related disadvantage, the central control module of the conventional LCS fails to give an adequate indication of the operating status of the electrical appliances. To obtain such an indication, the user must travel to each electrical appliance for direct observation. Moreover, if modification of the operating status of a particular electrical appliance is desired after such observation, the user must travel from the electrical appliance to the central control module. Each time the operating status of an electrical appliance is first observed and then altered necessitates attendant travel by the user. The inefficiency associated with repeated travel between the electrical appliances and the central control module is especially grave in physically large environments.
Efficient control of the electrical appliances and associated appliance modules is also precluded by the labor-intensive design of the conventional LCS. In certain circumstances, the user will desire to set the operating levels of a variety of electrical appliances so that they will cooperate to achieve a desired configuration. For example, the user of a conventional LCS in a home environment might want to turn on all lamps in the home every evening. As stated above, the operation of each electrical appliance is controlled by the central control module. Accordingly, to set a variety of electrical appliances to a particular configuration, the user must individually and successively control each electrical appliance. The operating status of each electrical appliance must be appropriately adjusted until all of the electrical appliances are satisfactorily programmed to attain the desired configuration. However, once the electrical appliances have attained the desired configuration, the configuration cannot be saved and easily retrieved at a later time. Rather, if the desired configuration is lost, the user must reset all of the electrical appliances individually, as when first programmed, until the configuration is reproduced. Therefore, the user in the example above would have to turn on all of the lamps individually to obtain the desired configuration every evening. Accordingly, the conventional LCS fails to provide a simple, efficient way to recall configurations.
Apart from its inconvenient and inefficient design, the conventional LCS is also unreliable. During installation, the user assigns the central control module one of 16 possible central control module codes to distinguish the central control module from a central control module of another possible LCS nearby. The central control module installs the various appliance modules under its control by assigning each of them one of 16 possible appliance module codes. The central control module code is used to identify the central control module to the appliance modules, while the appliance module codes are used to identify a particular electrical appliance to the central control module.
This method of installing the appliance module with the central control module is unreliable. First, the installation of the appliance modules is "one-way", i.e., the central control module transmits the central control module code and the appliance module code to the appliance module. However, the appliance module does not acknowledge its receipt of the code. As a result, if the codes are not successfully received by the appliance module, the user of the conventional LCS is given no indication of the installation failure. In that event, the user is left with the uncertain presumption that the appliance module has been correctly installed, as well as the negative consequences of such a presumption.
The relatively small number of available installation codes also negatively impacts the operational reliability of the conventional LCS. In some instances, the identities of the central control module and the appliance modules will be confused, complicating proper operation and control of the appliance modules. It will be appreciated that, in certain undesirable circumstances, a conventional LCS may sometimes be communicatively linked to another LCS. Typically, this occurs when the LCSs are situated adjacent one another while sharing a communication medium. Because only 16 codes are possible to identify a particular central control module, it is quite possible that two neighboring central control modules, associated with the two neighboring LCSs, may share a common central control module code. In that case, the appliance modules of both LCSs would have no ability to distinguish the commands originating from one central control module from the other. The electrical appliances of one LCS would then be susceptible to the control of the other LCS, and vice versa. Consequently, the reliability in the control of the electrical appliances would be significantly compromised.
The provision of only 16 appliance module codes results in analogous disadvantages. If the number of electrical appliances in the particular region served by the conventional LCS exceeds 16, as is often the case, some of the appliance modules would have to share a common code. Accordingly, because an appliance module could not be definitively identified by a unique corresponding code, the ability to reliably control such an appliance module, and only that module, would attendantly suffer. Commands from the central control module that are intended to control one appliance module could instead be misdirected to control another appliance module.
In light of the foregoing disadvantages of the prior art, a new and improved LCS is needed. The present invention is directed to meeting this need by providing an inexpensive LCS that is both reliable and convenient to use.